A prior art valve enclosure assembly is shown generally at 10 in FIG. 1. Valve enclosure assembly 10 is preferably coupled to a pump 12. The pump 12 is preferably electrically powered by common household current through cord 13. The pump 12 is mounted on a base 14. An air inlet 16 defined in the base 14 provides inlet air to the pump 12. Pressurized air is discharged from the pump 12 into the valve enclosure assembly 10 through an air outlet 18 defined in the rear face of the valve enclosure assembly 10. A processor board 20 is mounted on the upper surface of the pump 12. A left pressure sensor 22 and a right pressure sensor 24 are mounted on the processor board 20.
The prior art valve enclosure assembly 10 is formed of two major subcomponents; enclosure 26 and front face 28. The enclosure 26 has four sides and a rear face. After the various valve components have been mounted within the enclosure 26, the front face 28 is chemically bonded to the enclosure 26.
A right air outlet 30 is defined within outlet sleeve 32. A left air outlet 34 is defined within the left outlet sleeve 36. The outlet sleeves 32, 36 are formed integral with the front face 28 and project outward therefrom such that an air hose may be slipped over the outer surface of the outlet sleeves 32, 36. A monitor port 38 may be formed on the outlet sleeve 32. The monitor port 38 is fluidly coupled to the right air outlet 30. Likewise, a monitor port 40 is formed on the outlet sleeve 36 and is fluidly coupled to the left air outlet 34. Pressure monitor tubes 42 couple the outlet sleeves 32, 36 to the right pressure sensor 24 and the left pressure sensor 22, respectively.
A right and left solenoid (not shown) are mounted within the prior art valve enclosure assembly 10. Each solenoid has a shiftable plunger (not shown) coupled thereto. A sealing disk (not shown) is mounted on the end of the plunger. In the closed configuration, the sealing disks close the right air outlet 30 and the left air outlet 34 by sealingly engaging the inner peripheral surface of the respective outlet sleeves 32, 36. A coil spring (not shown) is mounted concentric with the plunger between solenoid and the sealing disk to bias the sealing disk to the closed configuration, thereby fluidly sealing the mattress off from the prior art valve enclosure assembly 10.
In operation of the prior art device, a command is received by the processor board 20 to inflate either the right or the left bladder of the mattress, as selected. The pump 12 is energized, drawing air in through air inlet 16, compressing the air, and discharging the compressed air into the valve enclosure assembly 10 through air outlet 18. The pressure differential between the commanded pressure and the existing pressure in either the right or left bladder is determined by the processor board 20 using inputs from either the left pressure sensor 22 or the right pressure sensor 24. The left or right solenoid is actuated opening the sealing disk on the right air outlet 30 or left air outlet 34, as selected, to inflate the desired bladder of the air mattress. While the bladder is being inflated, the solenoid must be periodically disengaged so that the sealing disk seats closing off the air outlet 30, 34 in order to provide to the processor board 20 a reading of the existing pressure in the bladder.
While the prior art valve enclosure assembly 10 has proved to be a useful device, certain problems existed. The sealing disk on the solenoid has a considerable area. The pressure in the bladder of the air mattress constantly acts upon the area of the sealing disk, generating a significant force thereon. Accordingly, the coil spring biasing the sealing disk into the closed configuration must have substantial strength in order to counteract the force exerted by the pressure in the bladder of the air mattress. This further necessitated having a very large solenoid to overcome the bias of the coil spring in order for the solenoid to unseat the sealing disk and open the valve. Such solenoids were prone to overheating. Additionally, with the need to periodically seat the sealing disk in order to monitor the pressure in the bladder the solenoid needed to be actuated many times while a bladder was being inflated, further adding to the heat buildup.
A further problem was that, since the pressure in the bladder was constantly acting on the sealing disk, the sealing disks tended to develop leaks around the periphery resulting in the slow deflation of the bladder. Over time, the sealing disks acquired a layer of dust that contributed to the leaky condition.
Accordingly, there is a need in the industry to minimize bladder leaks, to provide for continuous monitoring of existing pressure in a bladder of the mattress, and to provide for increased production efficiencies. Such production efficiencies include reducing assembly time and eliminating chemical sealants on the valve air enclosure.